PVCs while falling asleep

I've read lots about PVCs on this forum and elsewhere and I have a biology background. Fatigue is usually listed as a predisposing factor for PVCs. I get long bouts of quadrigeminy and sometimes bigeminy PVCs at night. I wake up exactly at 4AM every night and get them for about two hours straight. Sometimes I can get them to settle down, but then as I drift off to sleep they immediately start again with a jolt. I've been reassured by physicians about the harmlessness of PVCs so often that they don't make me so much anxious as they just mechanically perturb me so that every time I start to drift off to sleep--POW! Can you explain to me what it is about fatigue and especially drifting off to sleep that precipitates PVCs so profoundly? Any information which shows involvement of the reticular activating system in heart electrophysiology? I take 10 mg propanolol and 0.5 mg Klonopin daily. They don't seem to help reduce the PVCs and in fact I think they actually disturb my sleep more. I never feel rested.

[Cleveland Clinic]

PVC often come up more during periods of bradycardia.  This happens because normally they are overdriven by the sinus node, but once the sinus rate goes down it allows the irritable foci in your ventricular myocardium to take over.  PVC's aren't very dangerous, but they also aren't benign.  If the meds aren't helping control them, there are other means of eliminating them such as an ablation procedure.  We only do this in patients who have symptomatic PVC's, such as yourself, and in those in whom the PVC burden is so high that it causes whats known as tachycardia induced cardiomypathy.  We usually have our patients wear a holter monitor for  a 24 hour period and if the PVC burden is greater than 15% an ablation is recommended.  In you, I would even say that because you are so symptomatic form the PVC's and the medicine isn't helping, you warrant an ablation at this point.